Before going on vacation in the mountains, remember to take a total screen and protect yourself from the sun. Sunburn caused by excessive exposure to UV rays is an important risk factor for developing melanoma. Melanoma is the most dangerous skin cancer due to its ability to form metastases in vital organs like the brain, liver or lungs.
UVB, UVA: both are dangerous
Previously very rare, melanoma is currently the cancer with the fastest progression. Sunburn caused by excessive exposure to UV rays, at the beach or in the mountains, is an important risk factor for developing melanoma. Especially when these burns occur repeatedly during the first years of existence. For example, women who suffered five or more sunburns between the ages of 15 and 20 were up to 80% more likely to develop melanoma later in life.
It was long believed that only UVB rays could induce the development of melanoma. But recent research clearly shows that UVA rays also contribute to this cancer. Although less energetic, UVA rays trigger the production of free radicals in the skin and this oxidative stress can support the progression of melanomas.
It is also for this reason that indoor tanning, which uses high doses of UVA, is associated with a very significant increase (75%) in the risk of melanoma. It is therefore very important to avoid excessive exposure to the sun during holidays or to tanning lamps, because UV rays, whether type A or B, are formidable carcinogens.
Melanoma: a very aggressive cancer
Melanoma has the particularity of being able to spread throughout the body in the form of metastases. They will compromise the function of vital organs and put the life of the affected person in danger. This invasive nature of melanomas would be a consequence of the inflammation of the skin that accompanies sunburn. When skin cells are damaged by UV rays, they release alarm signals that attract a class of immune cells (neutrophils), which leads to the creation of a highly inflammatory climate.
These conditions activate cancer cells and cause them to attach to the surface of blood vessels, which they use as support to ‘crawl’ and achieve travel to other areas of the body. This new phenomenon, “metastatic dissemination by extravascular migration” means that melanomas can travel great distances without even having to enter the bloodstream.
In other words, if sunburn is an important risk factor for melanoma, it is because it promotes the appearance of cancerous cells and at the same time provides them with the optimal conditions for them to spread in the body. whole body.
Sunscreen in suitcases before going to the mountains
A little sunlight is essential to produce vitamin D, but 5 to 15 minutes of occasional exposure of the hands, face and arms to the sun, two or three times a week, is more than enough to maintain this vitamin at optimal levels. for health.
To reduce the risk of melanoma, it is essential to avoid unnecessary exposure to the sun. We recommend the use of sunscreens with a maximum sun protection factor as soon as you are exposed for more than 15 minutes, during the winter holidays during assembly, for example. Screens that protect against both UVB and UVA have appeared and these products represent a very interesting option for people who have to spend long periods in the sun as part of their activities or hobbies.
Wu S et al. Long-term ultraviolet flux, other potential risk factors, and skin cancer risk: a cohort study. Cancer Epidemiol Biomarkers Prev. ; 23: 1080-9.
Bald T et al. Ultraviolet-radiation-induced inflammation promotes angiotropism and metastasis in melanoma. Nature 109 -13